His Mistake
by Enx2103
Summary: Casey makes Derek pay for another mans's mistake. Derek he gives Casey an ultimatum...R&R Better then summary!
1. Chapter 1

**Truman's mistake.**  
**Disclaimer:** I don't own anything.  
Inspiration: His mistakes by usher. (go listen to it!)

Chorus:  
And it`s killing me girl you compare me to him  
Always guilty before the sin  
I can`t win, I can`t win  
I`ll do anything to prove I love you  
Baby girl would I refuse to  
Pay for something I didn`t do  
I love you, girl  
But I refuse to stay  
Paying for his mistakes

* * *

He crept downstairs hoping she was asleep on the couch. He really didn't want to get into it again; he really didn't want to hear the same old things from her. At first it was sort of cute, he liked the fact that she loved to claim her territory, as he did to her. But after a while he was sure of what was his, he excepted the same from her- but he was wrong.  
He made it to the landing without making a sound, he slowly picked up his leather jacket when she spotted him.

"Where the hell do you think your going?" she said. She was sitting on the couch with a cup of coffee in her hands, eyeing him down like he was in trouble.

He sighed and dropped his jacket back onto the hook- he knew he wouldn't be leaving anytime soon.  
"Out." He said simply making his way towards her, taking a seat in front of her on the coffee table.

"With who?" She continued to question.

"The guys."

"Likely story," she said rolling her eyes to his response.

"Case, you're driving me crazy," he said as calmly as he could.

"The feeling mutual babe," she said with a look of disgust.

"And I think the problem is this," he said taking her left hand and looking down at the engagement ring he had gotten her a few months ago.

"MY RING? No no no no no! Not my ring Derek," she said pulling her hand away.

"Yeah case. See once I gave you the ring, you realized this- us, we were going somewhere. We were serious and had a future together. And that scared the shit out of you didn't it?" He said smiling knowing fully well he was right, but also knowing she would deny it to no end.

"That's a lie Derek! This has nothing to do with it. The real problem here is that you go out all the time and the girls and the phone calls and the rumors and-"

"No. it's the ring. It's the commitment. Casey McDonald you're scared of commitment."

She crossed her arms over her chest. "Whatever," she mumbled.

"He hurt you case," he said gently taking her hands into his. "I understand that completely. But honey, you think I'm him. You think I'm going to do what he did. I'm not that stupid case, I know what I have and I know ill do anything to prove I love you. But Casey you can't punish me for something he did, that just not fair. "

"Im not punishing you!" she yelled.

"Casey your constantly on my back because you think im going to cheat on you, paying for his mistake. It hurts that you can even compare me and him case. I'm not Truman, that guys scum and I'm starting to think that's what you think of me."

"That's not true Derek," she said softly.

"Its not?"

"Of course not. I love you!"

"You loved him too case. You still might." He said quietly pulling away from her.

"How can you say that Derek? After what he did to me?"

"You can still love someone even if they hurt you. Look at me, I'm in love with you, aren't i?"

"Are you saying I hurt you ?"

"Everyday that goes by that you don't trust me- yeah it hurts case," he sighed. "Look case," he said sliding the ring off of her ring finger and placing it on the table. "If you trust me, when I get back that ring won't be here -but on your finger. But if you don't trust me…. it'll still there when I get back." He said sadly kissing her goodbye and putting on his leather jacket.

"What if I don't trust you, and the ring stays there?"She asked quietly.

He shrugged his shoulders. "Then it's over case."

* * *

He got home and stood at their front door nervous. _Nah she took the ring_ _back _he convinced himself. She loves him and she can trust him too. He thought unlocking the door. The slowly walked over to the coffee table where her engagement ring laid, right where he left it with a note beside it.

_I need to trust myself before I can trust anyone else  
Its gonna take some time  
I'm really sorry  
Love always  
Case*_

He let the note fall to the ground as a tear drop slipped out. He slowly picked up the ring, and realized she wasn't coming back.

* * *

AN: Its sad but i loved it. **REVIEWS**?


	2. Chapter 2

**Chapter 2**  
**Disclaimer:** Still don't own anything.  
**Inspiration:  
**Whats a man to do by Usher-

What's a man to do  
When he's loving two  
But he can't keep his heart  
In two different places  
In two different places

* * *

"DEREK!" she yelled from across his apartment. He rolled his eyes and ignored her.

"Derek! Jeez I come over and all you do is stay locked up in this room!" she complained form the door.

"Is there a problem?" He asked staring at the computer screen in front of him.

"There is actually," She said walking towards him. She spun his chair to face her and pecked his lips. "Were going out tonight," she said smiling brightly.

"Umm sorry Tiff- WE'RE not going anywhere. Go have fun with your friends," he said turning his chair towards the screen once again.

"Aww come on Der- we never do anything!" she said leaning against the desk- crossing her arms over t her chest.

"It didn't bother you before," he said turning towards her.

"Fine. If we're going to stay in," she said unbuttoning his white shirt. "Can we at least go to bed?" She said with a sparkle in her eyes. He felt bad. He had been a real jerk to her lately. She didn't deserve it. Sure she wasn't perfect- he didn't expect her to be. But she didn't deserve the current treatment he was given her.

"Sure babe," He said smiling up to her, taking her hand.

***

He continued to kiss down her neck hearing her moan in response as well as her nails scratching his back. "I love you," she barley whispered.

"Love you too." he mumbled, not really paying attention to what she had said. He pulled away from her body and over to the nightstand next to his bed. He felt around until he found what he was looking for.

"Derek," she winced getting very impatient.

"Hold on," he said trying to open up the foil packet.

She looked over to him and realized what he was doing.  
"Derek baby, no," she said taking it away form his hands

He looked at her confused. "What? You're on the pill now?" He asked.

She giggled a bit."No Derek, But I want a baby." She said smiling up at him.

***

"Derek, I'm sorry!"

"Did you even think to yourself 'hmm maybe I should tell Derek' you know BEFORE hand!" he yelled.

"Honey, please don't be mad," she pleaded.

"Tiff, I think its best if you went home." He said running his fingers through his hair.

She bit her lip. "I was hoping to sleep over tonight." She said quietly "Please? I'll make it better." She said hopeful.

He sighed. "Fine. But don't think for a minute that were having sex tonight." He said looking at her with disappointment.

***

He looked at the alarm clock next to him, it read smiled remembering all the times Casey made him wish on 11:11. He missed her so much. He turned and saw Tiffany peacefully sleeping. And he instantly felt guilt. He knew his heart was still Casey's, and that Tiffany was trying really hard to win him wasn't stupid- she knew there was someone else. But he did love her- that he couldn't deny. But it just wasn't right. It wasn't the same kind of love he felt for Casey. The unconditional love, were he'd do anything to please her. Sure he loved Tiff- but it wasn't enough, and it wasn't fair to her either.

At 11:11 he stared at the ceiling and thought _I wish I had my life back_, and closed his eyes.

He was finally dozing off until he heard his cell phone buzz on the nightstand. He yawned, rubbing his eyes and opened him phone to find a text message from Casey.

**I trust myself**

Before he had time to register what I meant he received another text message.

**I trust myself with loving you.**

He was putting together the pieces of what she meant. There last conversation- the last time he had seen her. And then came one final text message.

**I trust you.  
**

AN:**Review?** Cause i really love them =]

* * *


	3. Chapter 3

**Trumans Mistake**  
**Chapter 3**  
**Disclaimer:** Still don't own anything.  
**AN:**I decided I need to finish my other stories before starting new ones! Enjoy the last chapter!

* * *

"How do I know you mean it?" He asked her. He was worried. He didn't want to jump back into it when she could leave at any second.

Casey didn't ask him but he knew she was wondering about his love life without her. The truth was that a few days after she got in contact with him he broke up with Tiffany. He used the excuse of her little stunt. But it really was because Casey came back. And Tiffany could never amount to be half as amazing as Casey was. It was a no brainer.

"What do you want me to do to prove it to you?" she asked sighing. She understood his concern. She would be thinking the same in his position. She didn't know what possessed her to actually leave. But he was right. She was blaming him and treating him as if it was all his fault. But it wasn't.

When she left she took some personal time. She was determined to learn to trust again. And of course being Casey, she went to a few lectures and read way too many book. Essentially using her Kneer ways to figured everything out. She pulled away from everyone. Even her mom and Lizzie which were both surprised to find out she left Derek.

She finally came around a few months later. She was a whole new women! Well not really she was the same Casey as before, minus the Truman. He had ruined every relationship for her… She dated after him in college, but that never lasted long enough.

However being on the same campus as Derek meant she saw a lot of him… frequently than expected actually! After a while they started to bond and hang out. One night he demanded her to stop her serial dating. He claimed that he was tired of her breaking her own heart. He also whined about her usually being too heartbroken to pay attention or even react to the pranks which he took so long to plan. He promised her that if she didn't stop, he'd find a way to ruin all of her relationships before she did. It was a joke obviously, but it was his way of admitting his feelings. And she couldn't help but go with it.

That was her story. The before and the after. But for now she needed to work on the future. She needed to prove to Derek that she was stable and not as crazy as before. She could trust him with a stripper on his lap at this point.

While she was gone she analyzed every bit of their relationship .She eventually realized there was nothing that gave her a legit reason to treat him that way. He was actually an amazing boyfriend. Of course that doesn't mean he stopped with the pranks or that they didn't fight. They were Casey and Derek after all!

"We'll take it slow," he whispered softly. She practically shivered at the shock of his lisp against the shell of her ear. _She had been gone way too long._

She smiled slowly. She'll prove herself to him. Because there's no one else she rather be with. There's was no one she would work so hard for.

"As slow as you want," she responded nodding. He gave in and pulled her into his arms for the first time in months. He missed her warmth. Her innocence still seemed to lie in her eyes. He also noticed that the pain that use to reside in those blue eyes seemed to be gone. He could only hope it was true, because he wasn't sure he could handle her leaving him again. Of course he wouldn't actually admit it; but he needed her.

They laid there for the rest of the night simply in each other's arms. Neither dared to move. They didn't need to kiss or do anything else. The simple comfort of being curled up in each other's arms watching hockey reruns was all they really needed.

* * *

**AN: **Too sappy? **Review!**


End file.
